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Topic: UCE 500 cams on AVL 500 ?? (Read 1974 times)

Hi, While awaiting the S cams, the urge to experiment seems to have taken over . Every time I see something new I end up wondering if this can be done - and more importantly will it be beneficial.

So the latest though which came to my mind was " Can the cams from the Classic (UCE model) 500 be used on the AVL 500 and will it improve the performance??"

The cams for the Classic seem to have smoother profile that the stock AVL cams and this thought keeps coming to me again and again - try it out. However, since I now have a pretty reliable running bike, I thought of bouncing off the idea with the experts here and see if anyone has tried out this before.

Hi TejK, Yes you can do this and gain some midrange and top end power [a couple of horsepower can be found], but be carefull to make sure they are timed in a manner so as not to make the valves contact the piston. Also, these cams will not fix the inlet valve 'bounce' at around 5,800 RPM, as I found out when I tried these cams and several other types as well, before discovering the 'S' type worked the best out of them all. Worth trying, though, as the 'Classic' type cams are readily available and very cheap compared to what I have to charge for the 'S' types, by the time I get them. B.W.

Hi BW, I have tried the CI cams on my bike any though there is a definite improvement, I switched back to the original cams as the top end speed remained pretty much the same. I think the wait and the price for the S cams will be worth it. Where its been around 6 months, whats a few more months till I get those

Dampking is right, I was actually referring to the UCE cams ( regret the misc description on my part).

I would take Ace's advice here. Believe it or not, TejK, I have had absolutely nothing to do with the UCE bikes [I don't think I have been any closer than a few feet away from the few I have seen] B.W.

I assume the one on the left of the first pic is a uce type, TejK? I have heard of the AVL cams being used as 'blanks' to make performance cams for the 'Iron' type Bullets, as there is plenty of material in them to achieve that. [just edited a possible clanger, but the pitch of the cam gear teeth look different to each other in that first pic] B.W.

Hi Pail/BW, Yes the one on the left is an AVL cam and the rounded lobe is the UCE cam. I have heard of people reprofiling the AVL cams for the CI engine. Unless done precisely, I am sure the lobes will end up with different cam timings than stock. However, haven't met anyone yet who has done so. The teeth on the cams are longer for the UCE and the pitch will be different for sure.

In the meanwhile, I had a spare set of AVL cams which on which I am filing/grinding off the base circle (painstakingly slow work) by 1.5 mm just as an experiment. I am aiming to have a slightly higher lift for the on the valves without altering the lobes. The slight change will definitely increase the lift and also the duration. I will have to check the base circle run-out very carefully to ensure uniform metal removal and flatness of the cam lobe surfaces ( w.rt. the follower).

I just can't help it - can't keep my hands off her and just need an excuse to touch her. And if I touch her at the right places, she just loves it and goes like a Bullet

Just curious, how do you anticipate to get more lift from the cam lobe by grinding it? You can definitely achieve more duration by doing so, but in order to get more lift you need to add material to your cam lobe and then reshape it. Are you by chance TIG'ing the lobes and reshaping them, or are you just working with what you already have there?

Just curious, how do you anticipate to get more lift from the cam lobe by grinding it? You can definitely achieve more duration by doing so, but in order to get more lift you need to add material to your cam lobe and then reshape it. Are you by chance TIG'ing the lobes and reshaping them, or are you just working with what you already have there?

Scottie

This can work to increase lift profile by reducing base circle, but it is a real shot in the dark, and would be considered "a hack job" by most mechanics.However, in India, this is the kind of thing that is normal everyday practice.

I used to be horrified at hearing stories like this from India, but after a while I got de-sensitized to it. Like the guy who cuts off the skirts of his pistons with a hacksaw, and welds up his chambers without having any clue about what kind of effects it has, and fitting pistons into bores without knowing what the clearances are, and stuff like that.

Apparently, there is no clue about what effect this is going to have on the piston or the valve springs(which are already insufficient for the stock application, much less getting more lift), what any of this is actually going to do to the engine, etc, etc.

When I read stuff like this, I usually just quietly disassociate myself from the thread.

Hi Scottie, I am no expert however, as I see it there are 2 ways of possibly increasing lift

1. Like you mentioned, adding material with welding onto the lobe top and regrinding. However, I don't think this is something I can try out as this would involve a lot of work and the results may not be controllable. And I don't have a welder with me.

2. The other option is to remove some material from the cam base circle which I can manage quite easily. And since i Had the spare cams sitting around, I tried it out. The logic or math behind it is something like this - A cam is a bump on a circle. When the lifter is riding on the circle, it's at zero lift. As the cam rotates, the lifter sides over the bump. Regrinding a cam is making the circle smaller, in order to make the bump bigger.

Have made an illustration to explain. Just imagine the follower starting from rest at the new base circle and getting lifted higher.